/Engine/Source/Runtime/Engine/Public/AudioStreaming.h
Manually prepare a chunk to start playing back. This should only be used when the Load On Demand feature is enabled, and returns false on failure.
virtual bool RequestChunk ( const FSoundWaveProxyPtr & SoundWave, uint32 ChunkIndex, [TFunction](API\Runtime\Core\GenericPlatform\TFunction)< void(EAudioChunkLoadResult)> OnLoadCompleted, [ENamedThreads::Type](API\Runtime\Core\Async\ENamedThreads__Type) ThreadToCallOnLoadCompletedOn, bool bForImmediatePlayback )